Introduction (vax-specific), Diskless NetBSD HOW-TO

Client hardware requirements

Supported models

Every VAX can be booted diskless if its CPU and network hardware is
supported by NetBSD.
Only the older VAX 11/7xx systems (this includes the VAX 8600) do not
support netbooting from the bootrom.
See note below.

Although a fairly broad range of systems is supported, this support
tends to come with certain limitations.

Display Limitations

The NetBSD/vax port presently has only support for the included
monochrome framebuffer in the VAXstation 2000 and VAXstation 3100.
There may be support for the GPX / QDSS color graphics in the future.
If your VAXstation is not configured for the monochrome framebuffer,
or it is a VAXstation 4000, you have to use the serial console.
You will either need a serial terminal such as a VT220, or
you will need to interface the VAX to another system such a PC running
a communications software package.

Setting up the client hardware

Determining your ethernet hardware address

You will need to determine the ethernet hardware address of your workstation.
This is sometimes also known as the "link level address" or MAC. It is a
twelve digit hexadecimal number (i.e. it uses 0-9 and A-F for each digit).
For example, 08:00:09:09:45:84 is the ethernet address of my
workstation.

When at the console prompt on your VAX client, entering the following
commands will output the ethernet address for the on board ethernet
adapter.

The DEBNA/DEBNT/DEBNK interfaces are called ET. On a 8200 they
are addressed as ETxn where x is BI slot number and
n is zero. The naming on the 6000 machines is quite different:

>>> BOOT /XMI:x /BI:y ET0

where x is the BI adapter going to the BI bus where ethernet
card sits and y is its slot number. The x is most
likely E or D. A SHOW CONFIGURATION shows a
list of cards so it's easy to find out those numbers even with closed
doors and without confusing D and E.

From now on the examples will use the ESA0 interface. Please replace
ESA0 in all following commands with the appropriate name of the interface
of your VAX system.

Also, you may try to use the command:

>>> show dev

Not all VAXen support this command. But all VAXstations, excluding the
VAXstation 2000 and II, all MicroVAX 3x00, III and VAX 4000 systems do.
If your VAX supports this command, you will get a complete list of devices
your VAX has, including the ethernet device with MAC address.

After the boot command has been issued,
you should immediately be prompted for a bootfile name. If the
bootloader is named MOPBOOT.SYS on your server, then enter in
mopboot and press return.

VAX 11/7xx systems (this includes the VAX 8600) using the DEUNA/DELUA
interfaces can not netboot from the bootrom. But the boot program can
use them, so you first have to load that program from console storage
(which is always present) and then as normal type

boot de(8,0,0,0)netbsd -s

or similar (this example was for an 11/750). You can skip the setup
of a mopd in this case.

Permanently overriding the default boot device

You need to change the name of
the bootloader on the mop server to be the ethernet address of the mop
client, as such:

# cd /tftpboot/mop
# ln -s boot.mopformat 08002b1659bb.SYS

Make sure that the hex letters [a-f] are lower case, otherwise
the VAX bootrom will not find the proper file. Now, when you netboot your
vax, it will not prompt you for a file name. The command you run is:

>>> b esa0

Some vax models support setting the default boot
device. The VaxStation 3100s (and possibly other models) will let you set
the default boot device to be the ethernet device. From the console
prompt, type:

>>> set boot esa0

After you set this, when these machines are rebooted, they will
automatically netboot without any user intervention.

How the bootrom starts loading from a diskless server

DEC intended for MOP (Maintenance Operations Protocol) to handle a lot of
network-related tasks, such as netbooting. Thus, it's built-in to most
(all?) VAX ROMs. To
keep things simple, the NetBSD folks have only implemented the
bootstrapping procedure, wherein the Boot ROM gets the
initial bootloader from a server.

The Boot ROM runs through a bunch of hardware checks

If your model of VAX supports setting the default boot device, then it
automatically broadcasts a mop request. Otherwise, each time you boot
your vax, you will need to tell it to send a mop request.

If it gets a response, it will download the NetBSD bootloader

The bootrom will transfer control to the bootloader and it will start
looking for a NetBSD diskless server (bootp then nfs. The old way
rarp, then bootparams, then nfs will be tried if bootp fails.)